Blank feeding method

ABSTRACT

A method of feeding a blank ( 31 ) by cutting a billet ( 11 ) for plastic working includes the steps of superimposing a plurality of annular members ( 15  to  18 ) having a coefficient of linear expansion smaller than that of the billet and an inside diameter slightly greater than the outside diameter of the billet on one another to assemble a tubular jig ( 12 ), inserting the billet into the assembled jig, heating the billet and the jig to a temperature at which the billet is half-molten, and cutting the billet into at least one blank by moving the annular members adjacent to one another in opposite directions. The cutting of the billet does not need a cutting tool, thus causing no wear of blades, and thereby allowing reduction in production cost. The billet can be cut into a plurality of pieces at a time, increasing productivity. Since the blanks can be fed together with the annular members, there is no need to reheat the blanks, providing increased productivity.

TECHNICAL FIELD

[0001] The present invention relates to a blank feeding method in whicha billet for use in plastic working is cut into blanks of apredetermined thickness and the cut blanks are fed to a press moldingdevice.

BACKGROUND ART

[0002] A method of cutting a billet into blanks is disclosed in, forexample, {circle over (1)} Japanese Patent Laid-Open Publication No.2001-321871, “Method of Press Molding Aluminum-based-composite Disc-likeParts.” A method of feeding blanks heated to a predetermined temperatureis disclosed in, for example, {circle over (2)} Japanese PatentLaid-Open Publication No. HEI-6-198413, “Solid-liquid-coexisting-rangeDie Casting Method.”

[0003] The press molding method of the conventional art {circle over(1)} will be described below with reference to FIG. 12.

[0004] First, alumina (Al₂O₃) powder is formed into a predeterminedshape in advance, being a porous alumina compact. Then, the compact isreduced and a molten aluminum alloy is infiltrated into the reducedporous structure, producing an aluminum-based-composite billet 101.

[0005] The aluminum-based-composite billet 101 is successively cut by acutter 102 to a predetermined thickness t, forming a blank material 103of the aluminum-based composite. Then, the blank material 103 is placedon a metal mold for molding.

[0006] In the cutting method of the conventional art {circle over (1)},however, the cutter 102 cuts the aluminum-based-composite billet 101with the blade of the cutter 102 wearing away soon, increasing thefrequency of replacement of the cutter 102, and increasing productioncost. The increased frequency of replacement of the worn-out cutter 102lengthens the stop time of the cutting machine, resulting in poorproductivity. Further, a machining allowance corresponding to the widthdimension of the cutter 102 is required, reducing the yield of theexpensive aluminum-based composite.

[0007] The die casting method of the conventional art {circle over (2)}comprises the following steps:

[0008] (a) first, a round bar is cut at a predetermined length, and acut material is put into a metal container with its internal surfacecoated in advance with a mold release agent;

[0009] (b) then, the material put in the container is heated in aheating furnace to a solid-liquid coexisting temperature range of thematerial. After the heating, the container containing the material isput out from the furnace and is carried to a sleeve insertion opening;and

[0010] (c) finally, the container is upset (inverted 180°), letting onlythe material fall into the sleeve, thus injecting the heated materialinto a mold cavity.

[0011] The use of the die casting method, however, requires the step ofinverting the container after heating the container to let the materialfall from the container, taking time for handling the material, andresulting in poor productivity. Further, the cutting work of cutting theround bar to a predetermined length of materials, producing a pluralityof materials from the single round bar takes time. Especially with around bar of a hard-to-cut material, the work takes time, increasingproduction cost.

DISCLOSURE OF THE INVENTION

[0012] It is an object of the present invention is to provide a blankfeeding method which allows increased productivity and thus allowsreduced production cost.

[0013] According to the present invention, there is provided a method offeeding a blank by cutting a billet for plastic working, which comprisesthe steps of: superimposing a plurality of annular members having acoefficient of linear expansion smaller than that of the billet and aninside diameter slightly greater than the outside diameter of the billeton one another to assemble a tubular jig; inserting the billet into theassembled jig; heating the billet and the jig to a temperature at whichthe billet is half-molten; and cutting the billet into at least oneblank by moving the annular members adjacent to one another in oppositedirections.

[0014] The billet expands by heating, eliminating clearance, contactingat its outer peripheral surface to the inner surface of the jig, andcausing a compressive force on the billet. With the compressive force,the jig holds the billet so as to prevent its moving inside the jig,causing no sliding in the axis direction, and facilitating the cuttingin the subsequent step. Heating the billet to a half-melting temperaturetogether with the jig reduces the shearing resistance of the billet. Asa result, the cutting of the billet in the following step isfacilitated.

[0015] In the step of cutting the billet into the blank, the billet iscut by half-melting the billet and moving the adjacent annular membersin the opposite directions, which eliminates the need for a cutting toolsuch as a cutter. As a result, there occurs no wear of blades caused byusing a cutting tool such as a cutter, incurring no purchase cost ofcutting tools.

[0016] Since the billet is half-melt and the adjacent annular membersare moved in the opposite directions, thereby to cut the billet, thereis no need to provide a machining allowance for cutting. As a result,yields of the billet are increased, reducing production cost.

[0017] Further, since the billet is half-melt and the adjacent annularmembers are moved in the opposite directions, thereby to cut the billet,the jig can cut the billet into a plurality of blanks at a time,increasing productivity.

[0018] In the step of disposing the blank on a press molding device, theblank, being fitted in the annular member, is carried to the pressmolding device, so that the blank can be disposed on the press moldingdevice before the temperature of the blank decreases, eliminating theneed for reheating the blank before molding.

[0019] In addition, since the blank, being fitted in the annular member,is fed to the press molding device, a locating portion of the annularmember can be brought to a locating portion of the press molding device,setting the blank in a predetermined position, and facilitating thepositioning of the half-molten blank.

[0020] In a preferred embodiment of the present invention, the blankfeeding method further comprises the step of disposing the blank, beingfitted in the annular member, on the press molding device.

[0021] The press molding device preferably has a mold half havingfitting holes for receiving the plurality of annular members with theblanks fitted therein, and the blank disposing step comprises fittingthe plurality of annular members into the fitting holes.

[0022] In another preferred embodiment of the present invention, theannular member has a grip protruding outward of an outer peripheralsurface, and the blank disposing step includes carrying the annularmember to the press molding device by holding the grip.

[0023] The heating may be performed by an induction heating method. Withthis, the heating time of the billet is shortened and the cycle time ofthe heating step is shortened.

[0024] The billet is preferably formed with an aluminum-based composite.The aluminum-based composite is cut by inserting the aluminum-basedcomposite into the jig and moving the adjacent annular members in theopposite directions, which eliminates the need for a cutting tool forcutting the aluminum-based composite. As a result, no cost occurs forpurchasing cutting tools to be subjected to severe wear for thealuminum-based composite. Further, since the aluminum-based composite iscut by moving the adjacent annular members in the opposite directions,no cutting tool is necessary for cutting the aluminum-based composite.As a result, there is no need to provide a machining allowance forcutting, increasing the yield of the expensive aluminum-based composite.

[0025] The jig is preferably formed with austenitic stainless steel.With this, an induction heating method can inductively heat only thebillet without inductively heating the austenitic stainless steel,enlarging the expansion difference, and increasing the compressivestress of the billet. As a result, the cutting in the subsequent step isfacilitated. The use of the austenitic stainless steel can apply acompressive force to the aluminum-based composite inside the jig by thethermal expansion difference because the coefficient of linear expansionof the austenitic stainless steel is smaller than the coefficient oflinear expansion of the aluminum-based composite.

BRIEF DESCRIPTION OF DRAWINGS

[0026]FIG. 1 is a flowchart of a blank feeding method according to thepresent invention;

[0027]FIG. 2 is a schematic perspective view illustrating an assemblingstep of a jig used for cutting a billet and a billet inserting step;

[0028]FIG. 3 is a plan view illustrating the billet inserting step;

[0029]FIG. 4 is a schematic diagram illustrating the step of heating thebillet to a half-melting temperature;

[0030]FIGS. 5A to 5C are schematic side views illustrating the step ofcutting the billet into blanks;

[0031]FIG. 6 is a partial schematic diagram of the blank fitted in anannular member before being fed to a press molding device;

[0032]FIG. 7 is a schematic cross-sectional view illustrating the blank,being fitted in the annular member, disposed on a lower mold half of thepress molding device;

[0033]FIG. 8A is a schematic cross-sectional view illustrating themolding of the half-molten blank disposed on the lower mold half in FIG.7;

[0034]FIG. 8B is a schematic diagram of a molded part resulting from themolding of the half-molten blank in FIG. 8A;

[0035]FIG. 9A is a schematic perspective view illustrating the way ofdisposing blanks on another lower mold half of the press molding device;

[0036]FIG. 9B is a schematic cross-sectional view of the blanks disposedon the lower mold half in FIG. 9A;

[0037]FIG. 10A is a schematic side view illustrating partially incross-section the molding of the blanks in FIG. 9B;

[0038]FIG. 10B is a schematic diagram illustrating molded partsresulting from the molding in FIG. 10A;

[0039]FIG. 11A is a schematic perspective view illustrating an annularmember according to a modification, with a blank fitted therein;

[0040]FIG. 11B is a schematic perspective view illustrating the way ofdisposing the annular member in FIG. 11A on a lower mold half accordingto another modification; and

[0041]FIG. 12 is a schematic perspective view illustrating theconventional billet cutting method.

BEST MODE FOR CARRYING OUT THE INVENTION

[0042] A blank feeding method according to the present invention will bedescribed with reference to FIGS. 1 and 2. In FIG. 1, ST denotes a step.

[0043] First, annular members 15 to 18 having a coefficient of linearexpansion smaller than that of a billet 11 are superimposed on oneanother, assembling a tubular jig 12 (ST01). Then, the billet 11 isinserted into the tubular jig 12 (ST01). Thereafter, the billet 11 andthe jig 12 are heated to a temperature at which the billet 11 ishalf-molten (ST03). Successively, the adjacent annular members 15 to 18are moved in opposite directions, thereby cutting the billet 11 intoblanks 31 of a predetermined dimension (ST04). Finally, the blanks 31,being fitted in the annular members 15 to 18, are disposed on a pressmolding device 32 (ST05).

[0044] Now ST01 to ST05 will be described in more detail especially withreference to FIG. 2.

[0045] First, the jig 12 used for cutting the billet 11 is assembled.Specifically, the jig 12 consists of circular press plates 13 and 14provided at its opposite ends for holding the opposite ends of thebillet, the first annular member 15, the second annular member 16, thethird annular member 17 and the fourth annular member 18 arranged in asuperimposing manner between the press plates 13 and 14, and bolts 21and 22 for uniting those annular members. The first to fourth annularmembers 15 to 18 are superimposed on the press plate 14 and the boltsare fastened, thereby assembling the tubular jig 12.

[0046] The first annular member 15 has an inner peripheral portion 15 aof an inside diameter Di slightly greater than the outside diameter Dbof the billet 11. An outer peripheral portion 15 b outside the innerperipheral portion 15 a is provided with a grip 15 c of a width W. Thegrip 15 c has a hole 15 d.

[0047] The first annular member 15 is formed with a material such asaustenitic stainless steel (e.g., JIS SUS304) having a coefficient oflinear expansion smaller than that of the billet 11. The second tofourth annular members 16 to 18 are each identical with the firstannular member 15 and will not be described. Reference signs 16 c to 18c denote grips of the second to fourth annular members 16 to 18, and 16d to 18 d denote holes of the annular members 16 to 18.

[0048] The billet 11 is formed with an aluminum-based composite, forexample.

[0049] The aluminum-based composite is made, for example, by forming inadvance alumina (Al₂O₃) powder into a porous alumina compact of apredetermined shape, reducing the alumina compact under an atmosphere ofmagnesium nitride, exposing the metal for good wettability, andinfiltrating a molten aluminum alloy into the porous structure. Thealuminum-based composite thus has good formability with the aluminum andthe reinforcing material firmly combined at an interface threrebetweenby chemical contact.

[0050] The billet 11 is successively inserted into the tubular jig 12 asshown by arrow {circle over (1)}.

[0051] After the insertion of the billet 11 into the jig, the pressplate 13 is placed on the first annular member 15 and the bolts 21 and22 are fastened as shown in FIG. 3.

[0052] The billet 11 is disposed with a clearance C equally providedbetween the outer peripheral surface of the billet 11 and the innerperipheral surface of the jig 12. The billet 11 may be disposed topartially contact the jig 12.

[0053] As has already been mentioned, the jig 12 is provided with theinside diameter Di slightly greater than the outside diameter Db of thebillet 11 so as to provide the predetermined radial clearance C betweenthe tubular jig 12 and the billet 11. Specifically, with the coefficientof linear expansion of the billet 11 as β, with the coefficient oflinear expansion of the jig 12 as α, with the temperature of the jig 12and the billet 11 at room temperature as T1, and with the heatingtemperature as T2, the clearance C is 2×C<(Db×β−Di×α)×(T2−T1).

[0054] The coefficient of linear expansion a of the jig 12 is α<β.

[0055] To meet those conditions, an aluminum-based composite is used asthe material of the billet 11 and austenitic stainless steel as thematerial of the jig 12. Since the coefficient of linear expansion of theaustenitic stainless steel is smaller than the coefficient of linearexpansion of the aluminum-based composite, the difference in thermalexpansion allows the application of a compressive force to thealuminum-based composite inside the jig 12.

[0056] The coefficient of linear expansion of the aluminum-basedcomposite is 19.3×10⁻⁶/°C., and the coefficient of linear expansion ofthe austenitic stainless steel (JIS SUS304) is 18×10⁻⁶/°C.

[0057] In FIG. 4, the billet 11 and the jig 12 are heated with aninduction heating means 23 to a temperature half-melting the billet 11.Reference numeral 24 denotes a mount for mounting the jig 12.

[0058] In the heating process, when the billet 11 and the jig 12 areheated to a temperature half-melting the billet 11, the billet 11thermally expands, the difference in expansion from that of the jig 12brings the outer peripheral surface of the billet 11 into contact withthe inner peripheral surface of the jig 12, and the confinement of thejig 12 causes a compressive force on the billet 11. As a result, nosliding in the axis direction occurs in the subsequent cutting step,facilitating the cutting.

[0059] Further, since the billet 11 and the jig 12 are heated to atemperature half-melting the billet 11 in the heating step, shearingresistance is reduced in the subsequent cutting step, facilitating thecutting of the billet 11.

[0060] In the heating step, the adoption of the induction heating methodcan shorten the time of heating the billet 11 and also shorten the cycletime of the heating step. Thus provided is an increase in productivity.

[0061] The adoption of the induction heating method and the use ofaustenitic stainless steel as the material of the jig 12 allow theinduction heating of only the billet 11 without inductively heating theaustenitic stainless steel, providing greater expansion difference, andincreasing the compressive stress of the billet 11. As a result, cuttingin the following step is facilitated.

[0062] Successively, when the billet 11 reaches the half-meltingtemperature, the induction heating means 23 is removed from the jig 12.

[0063] Now, with reference to FIGS. 5A, 5B and 5C, the step of cutting abillet into blanks according to the present invention will be described.

[0064] As shown in FIG. 5A, the jig 12 is used for starting cutting.More specifically, the bolts are removed to fit a pulling jig 25 in theopen holes 16 d and 18 d and fit a pulling jig 26 in the holes 15 d and17 d. The press plates 13 and 14 on the opposite ends are pressed via apressure-applying device 27 known by one of ordinary skill in the art tothe extent that the press plates 13 and 14 are not tilted when thepulling jigs 25 and 26 are pulled in opposite directions as shown byarrows {circle over (2)} and {circle over (3)}.

[0065] Then, as shown in FIG. 5B, the pulling jigs 25 and 26 are movedin the opposite directions as shown by arrows {circle over (2)} and{circle over (3)}, applying shearing forces to the billet 11 with thejig 12, and cutting the billet 11 into four pieces at a time.

[0066] The cut billet 11 provides blanks 31 fitted in the first tofourth annular members 15 to 18 as shown in FIG. 5C.

[0067] In this manner, in the process of cutting the billet 11 into theblanks 31, the second and fourth annular members 16 and 18 are pulledleftward (In the direction of arrow {circle over (2)}) and the first andthird annular members 15 and 17 adjacent to the second and fourthannular members 16 and 18 are pulled rightward (in the direction ofarrow {circle over (3)}), the second and fourth annular members 16 and18 and the adjacent first and third annular members 15 and 17 beingmoved in the opposite directions, thereby cutting the billet 11. As aresult, the billet 11 can be cut into four pieces at a time, allowingincreased productivity.

[0068] The second and fourth annular members 16 and 18 and the adjacentfirst and third annular members 15 and 17 are moved in the oppositedirections, thereby cutting the billet 11. As a result, the billet 11can be cut without using a cutting tool such as a cutter, reducingproduction cost.

[0069] When the material of the blank 31 is an aluminum-based composite,supply cost of cutting tools to be subjected to severe wear for thealuminum-based composite can be eliminated. Thus production cost can bereduced.

[0070] Further, since the second and fourth annular members 16 and 18and the adjacent first and third annular members 15 and 17 are moved inthe opposite directions to cut the billet 11, there is no need toprovide the billet 11 with a machining allowance for cutting, increasingthe yield of the expensive aluminum-based composite, and reducingproduction cost.

[0071] Now with reference to FIGS. 6 and 7, the step of disposing ablank on a press molding device 32 will be described.

[0072] The blank 31 is, as shown in FIG. 6, fitted in the first annularmember 15 by thermal expansion. With this state, by holding the grip 15c of the first annular member 15, the blank 31, together with the firstannular member 15, is carried to the press molding device 32.

[0073] Similarly, by holding the grips 16 c, 17 c and 18 c of the secondto fourth annular members 16 to 18 (see FIG. 5C), the blanks 31,together with the respective second to fourth annular members 16 to 18,are sequentially carried to the press molding device. The first tofourth annular members 15 to 18 may be carried by holding portions otherthan the grips.

[0074] As shown in FIG. 7, the press molding device 32 includes a mold33 consisting of an upper mold half 34 and a lower mold half 35. Afitting hole 36 is formed in the lower mold half 35. In the hole 36, thefirst annular member 15 is fitted. Although the figure only shows theone mold 33, the press molding device 32 has as many molds 33 as thesecond to fourth annular members with the blanks 31 fitted therein, forreceiving them. Since the blanks 31, being fitted in the first to fourthannular members 15, are carried to the press molding device 32 fordisposition, cooling time for taking the blanks 31 out of the first tofourth annular members 15 can be eliminated, resulting in increasedproductivity.

[0075] Since the blanks 31, being fitted in the first to fourth annularmembers 15, are fed to the press molding device 32, time between cuttingand feeding is shortened. The temperature of the blanks 31 thus hardlydecreases, eliminating the need for reheating the blanks 31 beforemolding. This allows an increase in productivity.

[0076] Successively, as shown in FIG. 8A, the upper mold half 34 islowered for press, forming the blank 31 into a molded part 37 of adesired shape. Then the upper mold half 34 is moved upward to take thefirst to fourth annular members 15 and the molded parts 37 out of thelower mold half 35. Finally, the molded parts 37 as shown in FIG. 8B aretaken out of the press molding device. The molded parts 37 are pulleycomponents in this embodiment.

[0077] Now with reference to FIGS. 9A to 10B, the way of disposingannular members with blanks fitted therein on another mold of the pressmolding device will be described.

[0078] As shown in FIG. 9A, the press molding device 32 has a pluralityof lower mold halves 41 of a flat shape each having locating portions 42and fitting holes 42 a. The blank 31, being fitted in the first annularmember 15, is fed to the press molding device 32, and is then positionedwith the grip 15 c inserted in the locating portion 42 as shown by arrow{circle over (4)}, and the first annular member 15 is fitted in thefitting hole 42 a as shown by arrows {circle over (5)}. Similarly, thesecond annular member 16 is positioned with the grip 16 c and fitted inthe locating portion 42 and the fitting hole 42 a, and the third annularmember 17 is positioned with the grip 17 c and fitted. As a result, thefirst to third annular members 15 to 17 with the blanks 31, 31 and 31fitted therein are disposed on the lower mold half 41 as shown in FIG.9B.

[0079] In this manner, the blanks 31, being fitted in the first to thirdannular members 15, 16 and 17, are fed to the press molding device 32,and then the grips 15 c, 16 c and 17 c are inserted into the locatingportions 42 of the lower mold half 41, which facilitates the positioningof the blanks 31. As a result, the precision of molded parts can beincreased without effort, and variation in dimension between moldedparts can be prevented, providing stable molding.

[0080] In the case of simultaneously molding a plurality of pieces asshown in FIG. 9A, the jig 12 (see FIG. 5B) is used to cut the billet 11into four pieces at a time as previously described, and then the blanks31, 31 and 31, being fitted in the first to third annular members 15 to17, are fed to the press molding device 32, so that the three blanks 31can be fed substantially at the same time, preventing variation intemperature between the blanks 31.

[0081] Successively, as shown in FIG. 10A, an upper mold half 43corresponding to the lower mold half 41 is lowered for press, therebyforming the blanks 31 into molded parts 44. Thereafter, the completedmolded parts 44 as shown in FIG. 10B are taken out of the press moldingdevice. The shape of the molded parts 44 is only an example.

[0082] Now, with reference to FIGS. 11A and 11B, the way of disposing anannular member in a modification on still another mold of the pressmolding device will be described. Components identical to those in theembodiment of FIGS. 2 to 6 are affixed the same reference numerals, andwill not be described.

[0083] As will be clear from FIG. 11A, a billet 11B is cut to obtain ablank 31B fitted in a first annular member 15B. The material of thebillet 11B is identical to that of the billet 11. The billet 11B has aplane surface 51 formed by cutting off a part of the circle. Thematerial of the first annular member 15B is identical to that of thefirst annular member 15. The first annular member 15B has a flat portion52 formed at an inner peripheral portion 15 a and a locating portion 53protruding outward of an outer peripheral portion 15 b.

[0084] As shown in FIG. 11B, a press molding device 32 has a lower moldhalf 54. The lower mold half 54 has two locating pins 55 and 56extending upward from the top surface. The blank 31B, being fitted inthe first annular member 15B, is carried to the press molding device 32,and then a grip 15 c of the annular member 15B is fitted onto thelocating pin 55 of the lower mold half 54 as shown by arrow {circle over(6)}, and the locating portion 53 of the annular member 15B is fittedonto the locating pin 56 of the lower mold half 54 as shown by arrow{circle over (7)}. Thereafter, the blank 31B fitted in the annularmember 15B is molded into a desired shape in a manner as describedabove.

[0085] The positioning of the blank 31B in this modification alsoprovides effects similar to those in the above-described embodiment.

[0086] The configuration of the induction heating means 23 in FIG. 4 isan example. A special furnace, for example, may be used.

[0087] The composition of the aluminum-based composite can be any, andmay be made by dispersing alumina (Al₂O₃) powder in a molten aluminumalloy.

[0088] The first to fourth annular members 15 to 18 are superimposed onone another to assemble the tubular jig 12. The number of the annularmembers is not limited to four and can be any.

[0089] The billet 11 is cut into four pieces with the jig 12 at a time.The number of cut pieces can be any.

[0090] The shape of the first to fourth annular members 15 to 18 can beany. For example, the inner periphery formed with the inside diameter Dimay be formed in a polygon, and the outer periphery may be formed in apolygon.

[0091] The configuration of the mold 33 in FIG. 7 is an example. Theshape of the fitting hole 36 formed in the lower mold half 35 is anexample.

Industrial Applicability

[0092] As will be apparent from the above, the blank feeding methodaccording to the present invention eliminates the need for a cuttingtool for cutting a billet, causing no wear of blades, and thus allowingreduced production cost of blanks for producing parts, and also feeds aplurality of blanks at a time without the need for reheating, thusallowing increased productivity of blanks. The present invention is thusbeneficial to parts-producing fields.

1. A method of feeding a blank by cutting a billet, comprising the stepsof: superimposing a plurality of annular members on one another toassemble a tubular jig, said plurality of annular members having acoefficient of linear expansion that is smaller than a coefficient oflinear expansion of said billet, said plurality of annular membershaving an inside diameter that is slightly greater than an outsidediameter of said billet; inserting said billet into said assembled jig;heating said billet and said assembled jig to a temperature at whichsaid billet is half-molten; cutting said billet into at least one blankby moving adjacent ones of said annular members in opposite directions;and placing said at least one blank on a press molding device with theblank fitted in the annular member.
 2. (Cancelled)
 3. The blank feedingmethod as set forth in claim 1, wherein said press molding device has amold half having fitting holes for receiving said plurality of annularmembers with said blanks fitted therein, and said blank placing stepcomprises fitting said plurality of annular members into said fittingholes.
 4. The blank feeding method as set forth in claim 1, wherein saidannular member has a grip protruding outward of an outer peripheralsurface, and said blank placing step includes carrying said annularmember to said press molding device by holding said grip.
 5. The blankfeeding method as set forth in claim 1, wherein said heating isperformed by an induction heating method.
 6. The blank feeding method asset forth in claim 1, wherein said billet is formed from analuminum-based composite.
 7. The blank feeding method as set forth inclaim 1, wherein said jig is formed from austenitic stainless steel.